-LRB- CNN -RRB- -- Former world No. 1 Roger Federer has paid tribute to his `` wonderful friend '' Ivan Ljubicic after the Croat announced on Wednesday he will end his 14-year playing career next month .

Ljubicic will retire from tennis after April 's Monte Carlos Masters , bringing the curtain down on a career which has seen him hit No. 3 in the world rankings , win the Davis Cup with Croatia in 2005 and collect 10 ATP Tour titles .

Sixteen-time grand slam winner Federer hailed Ljubicic , who won a bronze medal at the 2004 Athens Olympics , as a fearsome opponent , but said the time was right for the 32-year-old to hang up his racket .

`` I have a very good friendship with Ljubicic , '' Federer told the ATP Tour 's website . `` It 's been sad seeing him retiring really since I 've known about it for quite some time .

`` He 's one of the most feared players on tour ... He 's been a wonderful friend to me on tour , and it 's also been very beneficial to the game of tennis , not just on the court but off the court because he 's been part of the political system here .

`` We 've talked at length at times about it , but I think it comes at the right time for him and he 's in a perfect spot with his family . He 's just had a second daughter . He 's had a wonderful career . ''

Federer has played Ljubicic , who reached the semifinals of the French Open in 2006 , on 16 occasions over 10 years between 2000 and 2010 , losing three of those matches .

`` It 's never an easy decision for any professional athlete to retire , '' said Ljubicic , whose most recent title came at Indian Wells in March 2010 , an event which three-time champion Federer will play in next week .

`` I look forward to the next stage of my life . Tennis has given me so much and I want to continue to stay involved and contribute in some ways . ''

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Roger Federer has praised Ivan Ljubicic ahead of his retirement next month

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Croat Ljubicic will end his 14-year playing career after April 's Monte Carlo Masters

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Former world No. 1 Federer described Ljubicic as a `` feared opponent ''

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Ljubicic won the Davis Cup with Croatia in 2005 and rose to world No. 3 in 2006